In bowl of stand mixer fitted with a paddle attachment, beat margarine and sugar until creamy. Add aquafaba egg replacer and vanilla and beat again. Scrape down bowl.

Add flour blend, graham crumbs, baking powder, and xanthan gum and beat on low to combine. Increase speed to medium for 30 seconds to form a thick batter. Set aside.

For cream, in a clean bowl of a stand mixer, combine reduced egg replacer, guar gum, and cream of tartar. Using the whip attachment beat on high for about two minutes to consistency of lightly beaten egg white. Add sugar and vanilla, cover bowl with a kitchen towel and beat on high for 5 minutes, until stiff and glossy.

Scatter reserved batter by tablespoons over marshmallow cream in a random fashion, pressing down to flatter slightly. You won’t cover all marshmallow; you want some to show through. Sprinkle remaining 1/4 cup chocolate chips over top.

Bake 15-18 minutes or until batter is set and just starting to get golden and marshmallow is developing a matte skin. Don’t overbake, you want it gooey!

Transfer pan to wire rack to cool completely before cutting. Do not attempt to slice bars while still warm.